Immunochemotherapeutic research will be continued in order to develop new models for treatment of spontaneous and established tumors. Combinations of chemotherapeutic agents with both specific and non- specific activators of the immune system will be studied. Assays will be employed to monitor the tumor-host reaction during treatment with the various immunochemotherapeutic regimens. Studies of alteration of tumor cell antigenicity by drug will be conducted. These experiments will involve the study of classical histocompatibility antigens as well as the antigenic properties under the control of the Hh system. Emphasis will be placed on the athymic nude mouse model to develop a system of monitoring chemotherapeutic and immunological responses to allogeneic or xenogenic tumors.